1. Field of the invention
The present invention relates to flame retardant graft copolymer compositions, and more particularly relates to flame retardant graft copolymer compositions using a halogenated epoxy compound.
2. Description of the Related Art
Epoxy functional flame retardants, specifically epoxy functional brominated flame retardants, are known for enhancing the flame retardancy of graft copolymer compositions. Such compositions, however, have typically experienced undesirably high levels of viscosity during extended processing due to thermal instability of the compositions. Viscosity can be reduced by the addition of styrene-acrylonitrile rigid copolymer, but such an addition can undesirably lower the flame retardancy and dart impact strength of the compositions.
Accordingly, there is a need for flame retardant graft copolymer compositions which utilize an epoxy functional flame retardant, but which exhibit enhanced levels of thermal stability and desirable levels of dart impact strength and flame retardancy.